Add kops cluster YAML to initialize AWS IAM Authenticator

[ivanfetch]

The kops component will create a cluster ready for the AWS IAM Authenticator daemonset to be deployed. Pod volumes should be mounted to /srv/kubernetes/aws-iam-authenticator, as is typical in most kops implementations of AWS IAM Authenticator.

Using the AWS IAM Authenticator container image to create the certificate and Kubernetes API Server config avoids a cluster update, and allows managing the AWS IAM Authenticator daemonset outside of kops.

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[sudermanjr]

Is this something that should have a migration?

[ejether]

Yes, I think, based on our discussion at the last office hours, that it should.

[ejether]

I'll merge this and create a separate issue for the two migrations that need to be created.